A method and system for detecting and processing internal and external occlusion of a vehicle-mounted laser radar

Abstract

The present invention belongs to the technical field of intelligent vehicles, and provides a method and system for detecting and processing internal and external occlusion of a vehicle-mounted laser radar, including: acquiring an echo waveform signal of a laser radar in an automatic driving system; determining whether a window piece of the laser radar is blocked according to the echo waveform signal, and determining whether it is internal or external occlusion; directly determining internal and external occlusion according to a comparison between an echo width value of the echo signal and a threshold, and a comparison between the echo width and the threshold under a preset echo distance, and being able to directly perform occlusion detection and determine the type of occlusion during vehicle driving without the need for additional components such as cameras, and in the case of internal and external occlusion, respectively heating the window piece through a preset heating system, and cleaning the window piece through a preset cleaning device, thereby ensuring the processing of the window piece in different occlusion types and ensuring safe vehicle driving.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent vehicles, and in particular relates to a method and system for detecting and processing internal and external occlusion of a vehicle-mounted laser radar. Background Art

[0002] LiDAR plays an important role in the autonomous driving system. Compared with other types of sensors, it has less environmental impact and is particularly suitable for use in environments such as darkness and strong light. However, during use, the inside and outside of the window may be blocked by unknown objects, such as internal condensation and external dirt, which limits the application of LiDAR and may even cause a loss of perception, thereby affecting the safety of autonomous driving.

[0003] Because the LiDAR window occlusion problem mostly occurs when the vehicle is driving, it cannot perform occlusion detection in a stationary environment, and adding cameras and other solutions will increase the vehicle design cost. Moreover, the causes and treatment methods of internal and external window occlusions are different. Occlusion detection and determination of occlusion types are the main problems that currently restrict the application of LiDAR in autonomous driving systems. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a method and system for detecting and processing internal and external occlusions of a vehicle-mounted laser radar. The present invention directly determines internal and external occlusions based on a comparison between the echo width value of the echo signal and a threshold, as well as a comparison between the echo width and the threshold under a preset echo distance. The present invention can directly perform occlusion detection and determine the occlusion type during vehicle driving without the need for additional components such as cameras. In the case of internal and external occlusions, the window piece is heated by a preset heating system, and the window piece is cleaned by a preset cleaning device, respectively, thereby ensuring the processing of the window piece in different occlusion types and ensuring safe vehicle driving.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] In a first aspect, the present invention provides a method for detecting and processing internal and external occlusion of a vehicle-mounted laser radar, comprising:

[0007] Obtain the echo waveform signal of the laser radar in the autonomous driving system;

[0008] According to the echo waveform signal, determine whether the window of the laser radar is blocked, and determine whether it is internal or external; wherein, internal and external blocking are determined based on the comparison between the echo width value of the echo signal and the threshold, and based on the comparison between the echo width and the threshold under the premise of a preset echo distance;

[0009] If it is an internal shading, the preset heating system is controlled to heat the window piece; if it is an external shading, the preset cleaning device is controlled to clean the window piece.

[0010] Furthermore, when the echo width of a certain number of point clouds is smaller than a threshold, it is determined that internal condensation has occurred in the window.

[0011] Further, when the echo distance is smaller than the distance threshold and the echo width is smaller than the preset width threshold, it is determined that external shielding occurs.

[0012] Furthermore, when the echo width is less than a threshold value and greater than a first preset value, heating is performed with a first heating power; when the echo width is less than the first preset value and greater than a second preset value, heating is performed with a second heating power; when the echo width is less than the second preset value and greater than a third preset value, heating is performed with a third heating power; wherein the first preset value is less than the threshold value, and the first preset value is greater than the second preset value, and the second preset value is greater than the third preset value; the first heating power is less than the second heating power, and the second heating power is less than the third heating power.

[0013] Further, if the rate of change of the echo width from the threshold value to the first preset value is greater than the preset rate value, heating is directly performed with the third heating power when the echo width is less than the first preset value and greater than the second preset value.

[0014] Furthermore, the preset cleaning equipment includes a water supply tank, a water pump, and a nozzle connected to the water pump and the water tank through a pipe; the nozzle includes a plurality of nozzles arranged around the circumference of the laser radar, each nozzle is connected to the water supply tank and the water pump by a pipe, and each pipe is provided with a control valve; when the vehicle speed is a first preset speed, a preset number of nozzles near the front part of the vehicle are opened during cleaning, and when the vehicle speed is a second preset speed, a preset number of nozzles near the front part of the vehicle and a preset number of nozzles away from the front part of the vehicle are opened during cleaning; when cleaning after the vehicle stops, all nozzles are opened; the first preset speed is greater than the second preset speed, and the second preset speed is greater than the third preset speed.

[0015] In a second aspect, the present invention further provides a vehicle-mounted laser radar internal and external occlusion detection and processing system, comprising:

[0016] The data acquisition module is configured to: obtain an echo waveform signal of a laser radar in an autonomous driving system;

[0017] The type judgment module is configured to: determine whether there is an obstruction phenomenon in the window of the laser radar according to the echo waveform signal, and determine whether it is internal obstruction or external obstruction; wherein, internal obstruction and external obstruction are determined according to the comparison between the echo width value of the echo signal and the threshold value, and according to the comparison between the echo width and the threshold value under the premise of a preset echo distance;

[0018] The processing module is configured to: if it is internal shading, control a preset heating system to heat the window piece; if it is external shading, control a preset cleaning device to clean the window piece.

[0019] In a third aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the internal and external occlusion detection and processing method of the vehicle-mounted laser radar described in the first aspect.

[0020] In a fourth aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein when the processor executes the program, the steps of the internal and external occlusion detection and processing method of the vehicle-mounted laser radar described in the first aspect are implemented.

[0021] In a fifth aspect, the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the steps of the internal and external occlusion detection and processing method of the vehicle-mounted laser radar described in the first aspect.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] In the present invention, internal occlusion and external occlusion are determined directly based on the comparison between the echo width value of the echo signal and the threshold value, as well as the comparison between the echo width and the threshold value under the premise of a preset echo distance. Occlusion detection and determination of the occlusion type can be directly performed during vehicle driving without the need for additional components such as cameras. In the case of internal occlusion and external occlusion, the window sheet is heated by a preset heating system and cleaned by a preset cleaning device, respectively, thereby ensuring the processing of the window sheet in different occlusion types and ensuring safe vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0025] Figure 1 This is a heating logic schematic diagram of Example 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of occlusion detection according to Embodiment 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of external occlusion detection in Example 1 of the present invention;

[0028] Figure 4This is a schematic diagram of the nozzle layout of Example 1 of the present invention;

[0029] Figure 5 Schematic diagram of nozzle quantity distribution in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0032] Embodiment 1:

[0033] As described in the background technology, the detection of occlusion of the laser radar window and the determination of the occlusion type during vehicle driving are the main problems that currently restrict the application of laser radar in autonomous driving systems. Based on this, this embodiment provides a method for detecting and processing internal and external occlusion of a vehicle-mounted laser radar, which determines the internal and external occlusion of the laser radar window by the waveform signal of the echo, and uses two different processing methods to handle the internal and external occlusion problems according to the internal and external occlusion types, thereby reducing the risk of failure of the device itself and meeting the actual scene application. Specifically, the method includes: first, obtaining the echo waveform signal of the laser radar in the autonomous driving system; then, according to the echo waveform signal, determining whether the laser radar window is occluded, and determining whether it is internal or external occlusion; finally, if it is internal occlusion, controlling the preset heating system to heat the window; if it is external occlusion, controlling the preset cleaning equipment to clean the window. Among them, internal occlusion and external occlusion are determined directly based on the comparison between the echo width value of the echo signal and the threshold, as well as the comparison between the echo width and the threshold under the premise of a preset echo distance. Occlusion detection and determination of the type of occlusion can be directly performed during vehicle driving without the need for additional components such as cameras. In the case of internal occlusion and external occlusion, the window piece is heated by a preset heating system, and the window piece is cleaned by a preset cleaning device, respectively, to ensure the processing of the window piece in different occlusion types and to ensure safe vehicle driving.

[0034] like Figure 1 As shown in the figure, when there is internal occlusion, the heating logic will be triggered to eliminate the internal condensation and restore the normal point cloud signal. The mechanism of internal occlusion, such as internal condensation, is that the high temperature and high humidity environment of the LiDAR suddenly changes to a low temperature and high humidity environment, which will form water vapor (i.e. fogging) on ​​the inside of the window. When the humidity reaches a certain level, liquid water (i.e. condensation) will form. Internal condensation will affect light transmission and generate noise.

[0035] Optionally, the inner occlusion detection strategy is, such as Figure 2 As shown, the laser radar processing unit ECU compares the width of the received echo signal with the threshold value. When the echo width of a certain number of point clouds is less than the threshold value, it is determined that internal condensation has occurred in the window. When the internal condensation fault is met, the internal status flag Window_Intblockage_status will be set to 1.

[0036] Optional, such as Figure 1 As shown in the figure, the internal occlusion elimination measures are as follows: the laser radar outputs the point cloud normally after power-on. When there is no occlusion, it has entered the pre-heating mode and stops heating after heating the window for 5 minutes. The laser radar performs fault detection in real time. If there is an occlusion fault, it enters the heating mode and heats the window for 15 minutes. If the occlusion disappears, the heating is stopped.

[0037] Optionally, a heating system is preset at the window plate, and the heating system may include a heating wire, a heating plate, etc. arranged near the window plate, and a power supply, a switch, a controller, etc. connected to the heating wire, the heating plate, etc.

[0038] During heating, if the heating temperature is too high, the temperature difference between the inside and outside of the window sheet will become larger. When the shielding disappears and the heating is stopped, condensation will reappear inside the window sheet in a short time due to the large external temperature difference. The reappearance of condensation in a short time will cause a blind spot for the vehicle to drive for a short time, increasing the accident rate. Therefore, it is particularly important to control the degree of heating. Based on this, in this embodiment, the heating power is adjusted according to the size of the echo width, specifically:

[0039] When the echo width is less than the threshold and greater than the first preset value, it means that the condensation is relatively light. At this time, heating is performed with the first heating power. On the basis of ensuring the removal of condensation, the problem of a sharp increase in the temperature difference between the inside and outside of the window piece is avoided. The heating power can be represented by the electric power provided to the heating wire, heating plate, etc.; when the echo width is less than the first preset value and greater than the second preset value, it means that the condensation is relatively heavy. At this time, heating is performed with the second heating power, and the problem of removing condensation and controlling the sharp increase in the temperature difference between the inside and outside of the window piece is comprehensively considered; when the echo width is less than the second preset value and greater than the third preset value, it means that the condensation is serious. At this time, the use of a serious laser radar requires immediate removal of the condensation. At this time, heating is performed with the third heating power to avoid accidents.

[0040] At the same time, the change rate of the echo width when the threshold decreases to the first preset value is judged. If the change rate is greater than the preset rate value, it means that the condensation situation will become serious in a short time. At this time, when the echo width is less than the first preset value and greater than the second preset value, heating is directly performed with the third heating power.

[0041] The first preset value is smaller than a threshold value, the first preset value is larger than the second preset value, the second preset value is larger than the third preset value, the first heating power is smaller than the second heating power, and the second heating power is smaller than the third heating power.

[0042] When there is external obstruction, the external cleaning device will be triggered to clean the lidar window; external obstruction will detect foreign objects on the surface of the window or obstructions within 15cm from the window.

[0043] like Figure 3 As shown in the figure, the external occlusion detection strategy is that the flight time and echo energy of the echo after the light emitted by the laser radar hits the target of different distances and reflectivity are different, corresponding to different echo distances and echo widths. By finding the echo distance and echo width characteristics of the close-range obstruction, the external occlusion of the laser radar is determined by threshold setting; for example, when the echo distance is less than the distance threshold and the echo width is less than the preset width threshold, it is judged that external occlusion occurs. When external occlusion is met, the internal status flag Window_Extblockage_status will be set to 1.

[0044] The external obstruction elimination measure is to trigger the preset cleaning equipment for foreign matter on the surface to clean the laser radar window piece for 3 times, each time for 20 seconds. In this embodiment, the nozzle is required to be arranged left and right, and can be extended and rotated up and down. After each cleaning, re-check whether the external obstruction is eliminated. If it is eliminated, stop cleaning.

[0045] In another embodiment, Figure 4 and Figure 5 As shown, the preset cleaning equipment includes a water supply tank, a water pump, and a nozzle connected to the water pump and the water tank through a pipeline; the nozzle includes a plurality of nozzles arranged around the laser radar, and each nozzle is connected to the water supply tank and the water pump by a pipeline, and each pipeline is provided with a control valve. Specifically, when the vehicle speed is the first preset speed, a preset number of nozzles near the front of the vehicle are opened during cleaning; when the vehicle speed is the second preset speed, a preset number of nozzles near the front of the vehicle are opened during cleaning, as well as a preset number of nozzles away from the front of the vehicle are opened during cleaning; when cleaning after the vehicle stops, all nozzles are opened. The first preset speed is greater than the second preset speed, and the second preset speed is greater than the third preset speed.

[0046] It is understandable that when the vehicle speed is fast, if the nozzle away from the front of the vehicle is opened in time, its water flow will be blown away by the wind and fail to achieve the purpose of cleaning the window piece, which will cause water waste. Through the above setting, water waste can be reduced while ensuring the cleaning of the window piece.

[0047] Embodiment 2:

[0048] This embodiment provides a method for detecting and processing internal and external occlusions of a vehicle-mounted laser radar on the basis of Embodiment 1. Optionally, after the laser radar is powered on, it outputs a point cloud normally. If there is no fault, it enters "preheating" and heats the window piece, and stops heating after 5 minutes. The laser radar performs fault detection in real time. If there is an occlusion fault and the temperature of the laser radar itself is lower than the threshold, it enters the heating mode and heats the window piece for 15 minutes. If the occlusion disappears, the heating is stopped. During the heating process, if there are other faults, the heating is stopped.

[0049] In humid winter, when entering the indoor environment from outside, the temperature difference causes condensation on the lidar window. After the lidar detects it, it outputs an internal occlusion signal and triggers the heating logic for 15 minutes. If the occlusion disappears, the heating stops; if the occlusion still exists, it will be reheated after 2 minutes until the internal occlusion disappears.

[0050] When the laser radar detects dirt outside the window in real time, it outputs an external occlusion signal and triggers a cleaning logic signal. The cleaning device cleans the laser radar window three times, each time for 20 seconds. The nozzles are required to be arranged left and right and can be extended and rotated up and down. After each cleaning, re-check whether the external occlusion is eliminated. If it is eliminated, stop cleaning.

[0051] The internal and external occlusion signals output by the lidar are used by the autonomous driving system controller as input to the safety strategy to downgrade or take over the autonomous driving vehicle being executed.

[0052] During the entire working cycle of the LiDAR, occlusion detection is real-time, and occlusion removal is performed according to the logic of heating and cleaning, ensuring that the LiDAR can adapt to applications in different weather and scenarios, greatly improving the scope of use of the LiDAR and providing the system with reliable and high-quality environmental perception information.

[0053] Embodiment 3:

[0054] This embodiment provides a vehicle-mounted laser radar internal and external occlusion detection and processing system, including:

[0055] The data acquisition module is configured to: obtain an echo waveform signal of a laser radar in an autonomous driving system;

[0056] The type judgment module is configured to: determine whether there is an obstruction phenomenon in the window of the laser radar according to the echo waveform signal, and determine whether it is internal obstruction or external obstruction; wherein, internal obstruction and external obstruction are determined according to the comparison between the echo width value of the echo signal and the threshold value, and according to the comparison between the echo width and the threshold value under the premise of a preset echo distance;

[0057] The processing module is configured to: if it is internal shading, control a preset heating system to heat the window piece; if it is external shading, control a preset cleaning device to clean the window piece.

[0058] The working method of the system is the same as the internal and external occlusion detection and processing method of the vehicle-mounted laser radar in Example 1, and will not be repeated here.

[0059] Embodiment 4:

[0060] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the internal and external occlusion detection and processing method of the vehicle-mounted laser radar described in Example 1 are implemented.

[0061] Embodiment 5:

[0062] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the program, the steps of the internal and external occlusion detection and processing method of the vehicle-mounted laser radar described in Example 1 are implemented.

[0063] Embodiment 6:

[0064] This embodiment provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the steps of the vehicle-mounted laser radar internal and external occlusion detection and processing method described in Example 1 are implemented.

[0065] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A method for detecting and processing internal and external occlusion of a vehicle-mounted laser radar, characterized in that: include: Obtain the echo waveform signal of the laser radar in the autonomous driving system; According to the echo waveform signal, determine whether the window of the laser radar is blocked, and determine whether it is internal or external; wherein, internal and external blocking are determined based on the comparison between the echo width value of the echo signal and the threshold, and based on the comparison between the echo width and the threshold under the premise of a preset echo distance; If it is an internal shading, the preset heating system is controlled to heat the window piece; if it is an external shading, the preset cleaning device is controlled to clean the window piece.

2. A vehicle-mounted laser radar internal and external occlusion detection and processing method as claimed in claim 1, characterized in that: When the echo width of a certain number of point clouds is smaller than the threshold, it is determined that internal condensation has occurred in the window.

3. The method for detecting and processing internal and external occlusion of a vehicle-mounted laser radar as claimed in claim 1, characterized in that: When the echo distance is less than the distance threshold and the echo width is less than the preset width threshold, it is determined that external occlusion occurs.

4. The method for detecting and processing internal and external occlusion of a vehicle-mounted laser radar as claimed in claim 1, characterized in that: When the echo width is less than the threshold and greater than the first preset value, heating is performed with the first heating power; when the echo width is less than the first preset value and greater than the second preset value, heating is performed with the second heating power; when the echo width is less than the second preset value and greater than the third preset value, heating is performed with the third heating power; wherein the first preset value is less than the threshold, and the first preset value is greater than the second preset value, and the second preset value is greater than the third preset value; the first heating power is less than the second heating power, and the second heating power is less than the third heating power.

5. A vehicle-mounted laser radar internal and external occlusion detection and processing method as claimed in claim 4, characterized in that: If the rate of change of the echo width when the threshold value decreases to the first preset value is greater than the preset rate value, heating is directly performed with the third heating power when the echo width is less than the first preset value and greater than the second preset value.

6. The method for detecting and processing internal and external occlusion of a vehicle-mounted laser radar as claimed in claim 1, characterized in that: The preset cleaning equipment includes a water supply tank, a water pump, and a nozzle connected to the water pump and the water tank through a pipe; the nozzle includes a plurality of nozzles arranged around the circumference of the laser radar, each nozzle is connected to the water supply tank and the water pump by a pipe, and each pipe is provided with a control valve; when the vehicle speed is a first preset speed, a preset number of nozzles near the front of the vehicle are opened during cleaning, and when the vehicle speed is a second preset speed, a preset number of nozzles near the front of the vehicle and a preset number of nozzles away from the front of the vehicle are opened during cleaning; when cleaning after the vehicle stops, all nozzles are opened; the first preset speed is greater than the second preset speed, and the second preset speed is greater than the third preset speed.

7. A vehicle-mounted laser radar internal and external occlusion detection and processing system, characterized in that: include: The data acquisition module is configured to: obtain an echo waveform signal of a laser radar in an autonomous driving system; The type judgment module is configured to: determine whether there is an obstruction phenomenon in the window of the laser radar according to the echo waveform signal, and determine whether it is internal obstruction or external obstruction; wherein, internal obstruction and external obstruction are determined according to the comparison between the echo width value of the echo signal and the threshold value, and according to the comparison between the echo width and the threshold value under the premise of a preset echo distance; The processing module is configured to: if it is internal shading, control a preset heating system to heat the window piece; if it is external shading, control a preset cleaning device to clean the window piece.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the vehicle-mounted laser radar internal and external occlusion detection and processing method as described in any one of claims 1-6 are implemented.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the program, the steps of the internal and external occlusion detection and processing method of the vehicle-mounted laser radar as described in any one of claims 1-6 are implemented.

10. A computer program product, characterized in that The computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the internal and external occlusion detection and processing method of the vehicle-mounted laser radar are implemented as described in any one of claims 1-6.

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